Tuesday, March 10, 2015

On pace for rapid warming, while Anthony Watts laughs at live dragons at WUWT...

"Never laugh at live dragons, Bilbo you fool!" he said to himself, and it became a favourite saying of his later, and passed into a proverb.
The Hobbit, Chapter XII, by J. R. R. Tolkien.Credit: Sascha Kozacenko (Sascha Kozacenko, with kind permission for GFDL.) Wikiquote

Today Anthony Watts has an article with the headline:

Laughable modeling study claims: in the middle of ‘the pause’, ‘climate is starting to change faster’

Then he put up the shonky chart from Roy Spencer and John Christy (see here and here), without identifying it or explaining how that pair managed to deceive the willing. Though he does provide a link to a WUWT article about it.

Anthony thinks it's really funny that global warming means that the world will most likely be heating up faster than ever in human history. Some say it will be at a pace ten times faster than any period in the last 65 million years.

Anthony writes: "From the models are better than reality department and the DOE/Pacific Northwest National Laboratory comes this ludicrous eye-roller." He is writing about a new paper in Nature Climate Change, by a team led by Steven J. Smith from the Joint Global Change Research Institute, Pacific Northwest National Laboratory.

The world will probably continue to heat up faster and faster

The paper is describing a study that was investigating the rate of temperature increase, particularly on the regional scale. The scientists were looking at changes we can expect over the span of a lifetime. The time periods they chose were forty years, representing about a generation and the planning time frame needed for major infrastructure projects (eg water storage, roads, bridges, outmoded electricity generation, etc).

Natural variability up to +/- 0.2°C in a decade

The team first worked out the pace of temperature change between 1850 and 1930. Over this time period people had started to keep records of surface temperature, but there hadn't been a huge rise in greenhouse gases. The scientists compared the rates of change over this time span with estimated temperature changes over the past two thousand years. The two thousand year temperature record was obtained from various reconstructions based on temperature proxies such as corals, ice cores and tree rings. This gave them a baseline of natural variability. For example, over North America and Europe, in any forty year period, surface temperatures can fluctuate by as much as +/- 0.2°C in a decade just from natural variation.

They compared the results to those of climate models and found they broadly agreed with the amount of natural fluctuation in surface temperature. This provided a measure of confidence in using models for projections.

The paper provides a lot of detail. For example, it discusses how models and PAGES2k reconstructions show differences between regions in regard to the amount of variability. (Australia has lower rates of change than some other regions, for example.)

Greenhouse warming has raised rate of increase in surface temperature

Having found broad agreement between climate models and records going back in time, the scientists then projected forward in time. They worked out 40-year rates of change between 1971 to 2020. What they found was, not surprisingly, that climate is changing faster now than it was in the past. For example, they found that over North America, surface temperatures increased at around 0.3°C a decade. This is more than can be attributed to natural variability.

Looking over the next forty years, the scientists found that temperatures will increase more quickly than it has in the past, even in low emissions scenarios. And in high emissions scenarios, surface temperatures will continue to rise at an increasing rate right through to the end of this century.

The chart below illustrates what the scientists found in regard to the rate of change of surface temperature in °C a decade. The rates are measured in 40 year windows of time, going from 1900 to 2100. The thick grey line shows the global rate of change. The others show the rate of change for the different regions of the world, with the Arctic sticking out like a sore thumb. North America and Europe also stand out from the rest.

Figure 3 | Past and future regional rates of change from CMIP5. Average 40-year rate of change: CMIP5 RCP4.5 scenario. Average over CMIP5 models for the regional rate of change. Rates of change in this figure are annual averages over land + ocean areas in each region. Source: Smith15

Remember this is rate of change of temperature, not temperature itself. And it's for RCP4.5, which, as the paper states, represents a world where global actions are taken to limit greenhouse gas concentrations. If actions are not taken to limit emissions then the rate of change increases for longer, before starting to flatten out around 2070.

Regional impacts and uncertainties

The reason the scientists looked at regional trends (see above) was because it's at the regional level that we'll need adaptation strategies. The global average doesn't say much about what will change where - which regions will be affected at which times and in what manner.

The paper itself goes into quite a lot of detail and discusses uncertainties such those surrounding aerosol forcings. It also mentions the current rate of change in surface temperature:

Like the projections from more complex models, these results do not capture the recently observed decrease in the rate of warming. Owing to internal variability, such a temporary slow-down is neither unusual nor unexpected, and is consistent with our analysis of historical rates of change where recent warming does not stand out when examined over 20-year time periods (Supplementary Fig. 2). The specific mechanisms at work are still a subject of research.

Temperature increase will intensify

It is the conclusions that are drawn which are of greatest concern. The research suggests that because of greenhouse warming, we are now going to be facing "background rates of climate change ... well above historical averages until at least mid-century." and that the "accelerated rates of change noted here mean that impacts related to rates of change will intensify over the coming decades".

Deniers suffer from rolling eyes

Anthony Watts rolls his eyes at these findings, though they are not inconsistent with what has been reported previously.

I can easily imagine that Anthony Watts' eyes roll around in his head a lot. He doesn't make much sense at the best of times. In this case, he seems to think it sufficient to write a silly headline and opening sentence on top of his usual lazy copy and paste of a press release. I say it's lazy, but really I think Anthony copies and pastes because he's not capable of understanding and interpreting science. He usually, but not always, knows his limits in that regard, unlike the interpreter of interpretations.

From the WUWT comments

As you can imagine, the WUWT comments spanned the spectrum from groans about using models to work out what the future will bring, instead of, say, tea leaves - through to an ice age cometh. Here's a sample:

Scottish Sceptic is a science denier and it looks as if he's a hard-core greenhouse effect denier who suffers bouts of hysteria:

March 9, 2015 at 9:12 am
Climate variation has not changed at all over the 350 years of CET.
Proof: recent temperature trends are not abnormal
However, I’ve now started look at HADCRUT4 and am seriously thinking there is a pattern suggesting marked cooling peaking around 2030.
So when I saw that above graph with a peak around 2030 I nearly split my coffee I laughed so much.

As usual, Scottish Sceptic is talking through his tam o' shanter. Below is a chart showing the large change in the temperature trend in recent years. It compares the trend from 1772 to 1950, which was around 0.2°C a century (blue trendline), with the trend from 1950 to the present, which is around 1.7°C a century (red trendline).

mikerestin demonstrated that he doesn't know how to read a chart. He wrote, in reference to the chart in the main article above:

March 9, 2015 at 11:12 am
Do they ever say why the rate of change flattens out and goes negative around 2030?
Is that when CO2 goes back to 350ppm?
Must be, eh?

Does anyone bother to correct him? Nope. (The chart doesn't go negative at all. The only times it got below zero were in the twentieth century.)

More than one person spoke about the scientists being on drugs. M Seward, for example, wrote:

March 9, 2015 at 9:23 am
Steven J. Smith, James Edmonds, Corinne A Hartin, Anupriya Mundra, and Katherine Calvin
Names to remember? I think not.
Did they analyse the relative contribution of ‘adjustments’ ?
Do you think they were off their medication?

Erny72 didn't bother reading the press release let alone the paper. He missed the parts about observations and 2000 years of temperature reconstructions. He also mistakes CMIP5 models for spreadsheets. Talk about "delusions of adequacy" - I'd say Erny wouldn't even make the cutoff to be accepted into a Dunning & Kruger experiment.

March 9, 2015 at 11:45 am
Five people in a ‘team’ and all they have to do is run a spreadsheet and press ‘update links’ once the sums are done by the computer model. They didn’t go out into the field and measure anything, nor even write any ‘cutting edge’ new model if I read this correctly. Just update links once the compuker finishes the number crunching.
So while one post graduate does that, what are the other four people doing? Sitting around repacking the bong or brewing up a new pot of herbal tea now and then?
What is written on the toilet walls above the bog rolls at Northwest laboratories? “Climate Science papers; please take one”?

Delusions of adequacy.

MarkW is an ice age comether:

March 9, 2015 at 9:34 am
With the sun past peak and beginning to slow down, they are going to need some serious adjustments to cover up the soon to come cooling.

pochas tries to sound sciency - about as sciency as any other crank from WUWT:

March 9, 2015 at 9:28 am
All these models assume the troposphere is in radiative equilibrium, when actually it is in convective equilibrium, unaffected by fluctuations in greenhouse gasses.

norah4you isn't concerned about learning how to spell, but she does think that WUWT-ers ought to learn some basic science. That is what she's saying, isn't it?

March 9, 2015 at 9:34 am
Wouldn’t it be cheeper for the world to send the uneducated back to school to learn Basic Math, Geology, Physic and Chemistry?
or else:
When will they ever learn?

March 9, 2015 at 11:58 am
1) Why are they using 1979-1983 average as the baseline? That’s a pretty narrow window.
2) Why does the plot stop at 2012 ?

He wasn't the only one who queried the chart. Makes you think that if Anthony had said it was prepared by Michael Mann, the fake sceptics would have been all over it pointing out the errors. Because it's from Roy Spencer, the deniers who know its shonky provenance give it a free pass.

There's a whole lot more, mostly from the 8% Dismissives who are incapable of writing anything more meaningful than "climate science is a hoax". You can read the comments here if you're curious.

14 comments:

At this point Tony Willard sounds like he's just waiting for the end of his gig, although I suspect there'll always be some tiny rump of elderly imminent ice-agers to keep some sort of website going. The Flat Earth Society, after all, yet survives.

What is is with deniers and "the pause"? Are they so collectively brain damaged that they can't understand the three simple concepts of signals, noises, and statistics?

I'm trying at the moment to get some of these numpties to address the issue over at Deltoid, but it's still not working. Short of simplifying it right down to "how will you know when the 'pause' is over?", I can't think of anything that could make them face the fundamental processes in interpreting a temperature data series.

Because the Global Mean Temperature flattened, and the rate of warming fell short of .2C per decade. In addition, the use of the words pause and hiatus and slowdown are commonly found in scientific papers about the period; there is a lot of effort expended to explaining the whatever.

The global mean temperature appeared to "flatten" when one looks at a graph depicting just one parameter that does not fully account for all thermal energy fluxes. Further, the "flattening" emerges only when short time intervals are considered, in ignorance of the inherent noise in the signal compared to the magnitude of the underlying trend.

The underlying effect of the signal-to-noise ratio of the dataset is such that an interval of at least twelves years is required to identify the trend from the noise, and depending on how heat sloshes around the global system, up to 20 years or more. This nmeans that for at least twelves years prior to any point in the global temperature record, there was a statistical pause. Put another way, with the current variability in the global temperature record it is entirely possible to have decade-on-decade warming and to never be able to statistically detect this warming for the previous 12-20 years.

The trouble is that the issue is grossly over-simplified by vested interests, by insufficiently scientifically-fluent reporters, and by the lack of understanding and/or by the apathy of the lay public.

But can one elicit from even a single global warming denier the mechanics of these points? To date the answer is a resounding "no".

I read pochas comment, and the immediately "Word Salad" popped into mind---essentially a bunch of legitimate words tossed together and plopped onto paper (in this case, screen) the same way you take pieces of vegetables and toss them in a salad so they're all higgledy-piggledy. Or all "jugga-jugga" as my Nigerian prof used to say as she waved her hands alternately up and down like she was juggling (think it meant all out-of-balance, messed up to the point of tragicomedy---no idea if Jugga was in reference to something in Jugga itself, and it was so confusing in Jugga it became a description.....darn it, now I'll have to find out).

Overall I liked the Smith et al paper, and I completely agree that it's the rate of warming that is a critical issue, and that there is a clear risk of warming rates that are unprecedented on millennial timescale. We wrote about the implications of this for biodiversity in my IPCC AR5 chapter.

However I think the headline figure of 0.25+-0.05 C / decade by 2020 is unlikely. It is not supported by IPCC conclusions, which take into account the recent slowdown in global warming (which, while probably temporary, will nevertheless affects the 40-year warming rate for a couple of decades or so).

I've written a short post about this at Ed Hawkins's Climate Lab Book - see here.

This doesn't affect the overall message of the Smith et al paper, that unusual rates of warming are a key issue. Overall I really like Smith's analysis. Nevertheless it's important to get the fine details right.

Understanding how tree growth is influenced by climate is vital for predicting how forests will respond to climate change, yet there have been few studies of tree growth spanning macroclimatic gradients. The aim of this study is to correlate growth of a single lineage of broadleaf evergreen trees with continental-scale variability in climate.

We compiled and analysed a dataset containing around half a million measurements of growth in eucalypt tree diameter, collected from 2409 permanent forestry plots. These plots spanned a range of 558–2105 mm mean annual precipitation and 6–22 °C mean annual temperature. Generalized additive models were used to study the relationship between growth in tree diameter and several temperature and water availability variables.

Results

Tree growth increased with precipitation, but with a diminishing response above a mean annual precipitation of 1400 mm. There was a peaked response to temperature, with maximum growth occurring at a mean annual temperature of 11 °C and maximum temperature of the warmest month of 25–27 °C. Lower temperatures directly constrain growth. High temperatures primarily reduced growth by reducing water availability, but they also appeared to exert a direct negative effect. Our best model, which included maximum temperature of the warmest month and the ratio of precipitation to evaporation, explained 28% of the deviance.

Main conclusions

The productivity of Australia's temperate eucalypt forests could decline substantially as the climate warms, given that 87% of these forests currently experience a mean annual temperature above 11 °C, where the highest growth rates were observed. This will reduce carbon sequestration and slow recovery after catastrophic disturbances such as wildfire.

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All you need to know about WUWT

WUWT insider Willis Eschenbach tells you all you need to know about Anthony Watts and his blog, WattsUpWithThat (WUWT). As part of his scathing commentary, Wondering Willis accuses Anthony Watts of being clueless about the blog articles he posts. To paraphrase:

Even if Anthony had a year to analyze and dissect each piece...(he couldn't tell if it would)... stand the harsh light of public exposure.

Definition of Denier (Oxford): A person who denies something, especially someone who refuses to admit the truth of a concept or proposition that is supported by the majority of scientific or historical evidence.
‘a prominent denier of global warming’
‘a climate change denier’

Alternative definition: A former French coin, equal to one twelfth of a Sou, which was withdrawn in the 19th century. Oxford. (The denier has since resurfaced with reduced value.)